Within the context of the present invention, the term “fuel” comprises all possible types of energy carrier, i.e. not only liquid fuel but also, in particular, gas and electricity. “Fuel filler necks” are therefore understood to be, in particular, as filler necks for liquid fuels as well as gas connecting nozzles and connecting nozzles for electrical energy.
In the field of motor vehicle technology, electromagnetically operative locking systems for closures, for example for vehicle body external flaps which cover fuel tank caps, are known which can be unlocked via a switch inside the vehicle or together with the central locking system. Fuel tank caps are also known which have a closure part which can be moved automatically by means of an electric motor between a closed position, in which the orifice of the fuel filler neck is closed, and an open position when the electric motor receives a corresponding opening and closing signal.
A drawback of known closure systems is that the fuel tank caps often remain open for an unnecessarily long time. As a result, gases, in particular, carbon dioxide, can escape from the tank interior into the atmosphere to an undesirably great extent. There is also the risk that a user will forget to close the fuel tank cap, as a result of which dirt, water, foreign bodies, etc. may enter the tank. In the case of electrically operated fuel tank caps, there is also often insufficient protection against trapping.
The object of the invention is to provide a method and a closure device with which it is possible to open and close a fuel filler neck in a manner which is optimised with respect to handling, the environment and security.